No one is going to be able to answer Nacho's question with an absolute certainty.

Anecdotely, I've shown a 50 cent receipt when I drove about 18 miles in Burlington, VT, and the gas gauge stayed pinned on FULL the entire time.

Showing my 50 cent receipt got the $13.99 EZ Fuel charged waived.

Their policy states, "This can be avoided if you've purchased fuel and provide us with a receipt." It doesnt say you have to provide a receipt with a certain dollar value, just that you have purchased fuel (which I did), and I provided a receipt (which I did).